How to Control Mountain Pine Beetle Infestation

Pine beetles, sometimes called bark beetles, are native insects of North America that have existed for thousands of years. They can be found in forests from Mexico to Canada, at all elevations. The insect is about the size of a grain of rice, but is capable of causing extensive damage to trees. Typically they bore into mature trees over five inches in diameter, and feed on the tissue that transports nutrients to the tree, thus interrupting the flow of water and killing the tree. Active forest management to control these insects is vital for trees to survive.

Instructions

• 1

  Manage the forest proactively as a method of prevention before infestation takes place. The pine beetle preys on old trees and prefers dense forests. Mature trees are twice as likely to become infested as young ones. Healthy forests are the result of diligent management of trees. When trees are varied in age and structure, they are much more likely to be able to withstand a pine beetle attack. There is not much that can be done once a tree is infested, except try to prevent further infestation to nearby trees.

• 2

  Kill larvae inside an infested tree by peeling away the bark. This is best done before the beetles develop into adults in the summer. If larvae are exposed to extreme conditions they will dehydrate, starve, and die. Burn infested logs to help eliminate the emergence of beetles that can damage other trees around them.

• 3

  Treat trees chemically by spraying the bark with persistent insecticides. Preventative treatments must be used before signs of infestation are evident. Usually it takes only one application a year to protect a tree for an entire season. Carbaryl and permethrin and sometimes bifenthrin are used as a preventative spray. The spray coverage area must begin at ground level and cover the entire circumference of the tree up to where the trunk tapers down in order to be effective.

• 4

  Place baits that attract beetles to traps. These baits contain natural pheromones that attract the insects. By trapping the beetles, it is then possible to detect a particular invasive species. Once the kind of species is determined it is then easier to utilize the best method of control. This method helps to eliminate or reduce bark beetle populations. Another prevention method is to use repellent pheromones to deter beetles away from healthy valuable trees, thus eliminating the possibility of infestation.

• 5

  Perform solar treatments on infested trees to help reduce beetle populations. Solar treatments only work on bark surfaces that are directly exposed to the sun. The temperature must get hot enough to kill beetles or dry out their habitat. There are two methods commonly used after the infested trees are cut down. One involves covering trees with plastic. The objective for both methods is to raise the temperature of the logs and increase the humidity and mold growth under the bark. High temperatures and mold help to deter or prevent normal beetle development. The method used without plastic as a cover works on the same principle, except that the logs are rolled periodically to ensure complete exposure to the sun on all surfaces.